1. Field of the Invention
The present invention relates to a gas turbine combustor and an operating method therefor.
2. Description of the Related Art
Gas turbines need to further reduce NOx emissions from the standpoint of environmental protection.
Measures to be taken to reduce NOx emissions from a gas turbine combustor include the use of a premixed combustor. In this case, however, there is concern about occurrence of a flash-back phenomenon, i.e., a phenomenon of flame entering the inside of the premixed combustor.
JP-2003-148734-A discloses a combustor configured to include fuel nozzles adapted to supply fuel to a combustion chamber and air holes located on the downstream side of the fuel nozzles and adapted to supply air. In addition, a jet hole of the fuel nozzle and a corresponding air hole are disposed on the same axis. This combustor achieves a balance between anti-flash back performance and low-NOx combustion.
JP-2010-133621-A discloses means for defining the outlet position and direction of an air hole and preventing flame from adhering to the outlet of the air hole. Unlike the disclosure of JP-2003-148734-A, a discharge amount of NOx can further be reduced by increasing a distance over which fuel and air are mixed with each other.